The present invention relates generally to cast-in features in concrete and related precast panels, and more particularly to an insert integrally-cast into a precast panel to allow decorative attachments to be affixed thereto, thereby improving the architectural attributes of the panel.
Precast construction of concrete wall panels for tilt-up and other types of construction is well-known in the art. In the tilt-up approach, forms, also known as form liners, are placed on a flat casting surface in the shape and dimension of the desired panel and filled with concrete. When the concrete cures, the forms may be removed, and the panel tilted up into a preferred, typically vertical, orientation, where it can be joined to structural frames or other panels. Additional structural reinforcements, such as rebar, can be placed within the form prior to pouring the concrete.
The present inventor has recognized a need for an insert that is inexpensive to manufacture and integrate into precast panels. An additional need exists for such an insert that can easily accept myriad attachments with minimal installation effort, yet secure enough to prevent the attachment from becoming decoupled once locked into place.
The need is met by the present invention, which comprises a panel insert used to provide connections in precast wall panels (generally) and tilt-up wall panels (specifically) such that attachments can be easily connected to the panel either prior to or once the panel is put in place. As used herein, a precast panel includes any panel that is formed from a cast material that upon curing hardens up, thereby allowing the panel to be subsequently placed in a desired location within a building structure. A tilt-up panel is a particular type of precast panel that is formed on a horizontal surface and tilted up into place upon curing of the cast material. The panel insert can take on many forms, including a long, continuous construction that can extend longitudinally substantially the entire length of a panel surface, or discrete, segmented pockets that can be easily integrated into a predetermined position within the panel. The degree of connection permanence between the insert and the attachment can be determined by the construction of the panel insert, specifically the attachment securing chamber portion of the insert. For example, a tapered attachment securing chamber geometry could permit a secure locking fit between the insert and the attachment, but still allow a slidable, non-permanent connection therebetween. Alternatively, a more permanent locking snap-fit could be effected by utilizing complementary engaging structures on the contacts between the attachment and the insert, and pressing the two of them together. The attachments, which are preferably used to present architectural and related decorative indicia, could also be utilitarian, as discussed below.
According to a first embodiment of the present invention, an insert configured to be integrally formed into a precast panel is disclosed. The insert defines a portion of the panel outer face, and serves as a place on the panel outer surface to which decorative and other attachments may be connected. The insert comprises a unitary structure made up of a pair of generally planar and laterally-spaced flanges defining an opening therebetween and an attachment securing chamber in connection with the flanges. In the present context, a structure is considered xe2x80x9cunitaryxe2x80x9d when it is of one-piece construction. By way of example, a one-piece molded or extruded plastic component would be considered to exhibit unitary construction. In the present embodiment, the opening is disposed in the surface that is at least partially defined by the flanges such that the opening and the attachment securing chamber together define a channel in the outer face of the panel insert. This channel may possess a short, discrete longitudinal dimension, or may form the entire length of the insert. Attachments may subsequently be connected into one or more channels of the attachment securing chambers in the panel insert.
Optionally, the channel further comprises at least one attachment retention member. Additionally, the attachment securing chamber may comprise a pair of laterally-spaced sidewalls joined by a common base. In addition, the attachment retention member can be configured to form either a slidably engageable or frictional connection with the attachment. Thus, the insertion of an attachment into the channel of the attachment securing chamber could be effected by not only a frictional pressing into place of the former to the latter, such as by a snap-fit, but also by a longitudinally slidable engagement. Moreover, the attachment retention member, which is used to ensure that the attachment and channel will maintain their connectivity once they engage, can take on many forms. For example, it can be made up of numerous prismatic retention members disposed on at least one surface of the attachment securing chamber such that the plurality of prismatic retention members are configured to engage a complementary surface of the attachment. Prismatic retention members could be triangular, saw-tooth or trapezoidal in shape, for example. Preferably, but not necessarily, the relationship between the prismatic retention members and a complementary pattern in the decorative attachment is such that a permanent lock can be formed. In the present context, a locking arrangement is considered xe2x80x9cpermanentxe2x80x9d where the connection between two members is such that they cannot be separated without severely curtailing or disabling their subsequent connective properties. In this configuration, a male-female connection could be effected by a snap-fit insertion of the prismatic retention members into the attachment securing chamber, where the prismatic retention members would resist separation from the complementary engaging surface of the attachment securing chamber once joined.
The attachment retention member can also be individual detents, or protrusions, emanating from one or more surfaces of the attachment securing chamber, or can be defined by a narrowness in the opening relative to the dimensions of the channel underneath. The latter can be achieved, for example, by a trapezoidal construction within the attachment securing chamber where the channel walls diverge in a direction going into the channel from the opening. This has the effect of having the sidewall of the inner surface of the attachment securing chamber being the retention member. Complementary shapes on an engaging member of the attachment (such as a detent) can then be slidably placed such that a secure connection is formed. The plurality of generally planar flanges can be configured such that they are substantially coplanar with each other, or where they are canted relative to each other. The insert may also include at least one inwardly-projecting spine extending from the attachment securing chamber or the generally planar flanges, in the latter case either by being laterally connected to the outer edge of the flange or somewhere off the inward-facing surface of the flange. This spine can be used to further engage the insert and the precast panel, and may further include a plurality of apertures therein to promote such engagement. Multiple such spines may be used to effect even more secure engagement.
According to another embodiment of the present invention, a panel insert is disclosed. The panel insert includes at least one each of an attachment securing chamber and a panel securing chamber, both defined by a pair of laterally-spaced sidewalls joined by a common base. The panel additionally includes a plurality of generally planar flanges laterally disposed relative to the chambers. The. panel securing chambers are coupled to the interior of the precast layer, as the panel material (such as concrete) can flow into the interstitial cavities defined by the panel securing chambers. Upon material hardening, a secure anchor is formed between them.
Optionally, the chambers are alternately juxtaposed relative one another such that the laterally-spaced sidewalls that are disposed therebetween are common to both. Preferably, the unitary structure is made of plastic, which is more preferably extruded, although other forms, such as injection molded plastic, may also be used. In such an extruded configuration, the generally planar flanges and the chambers are configured to extend along parallel longitudinal dimensions. To facilitate better attachment between the insert and the panel, at least one inwardly-projecting integral spine can be included on the insert such that it extends from one of the chambers or at least one of the plurality of generally planar flanges. The spine may also include a plurality of apertures disposed therein to facilitate improved connectivity with the precast panel since the precast material, upon curing, solidifies in and around the spine. Moreover, the plurality of generally planar flanges can be substantially coplanar with one another and the opening of the one or more attachment securing chambers. The attachment securing chambers include at least one attachment retention member disposed on at least one of the laterally-spaced sidewalls. The attachment retention member may be made up of numerous prismatic retention members disposed on at least one surface of the sidewalls such that the prismatic retention members are configured to engage a complementary surface of the decorative attachment. As an alternative to the prismatic retention member, the attachment retention member may be de fined by other geometric protrusions or extensions, each acting to limit the freedom of movement of the attachment along at least one Cartesian coordinate axis once it is connected to the attachment securing chamber. For example, as with the previous embodiment, the shape of the chambers can themselves function as the attachment retention member. One way to accomplish this is to have the respective openings in each chamber be substantially planar such that the opening defines a cross sectional area smaller than that of any parallel plane within the respective chamber. By making the chambers trapezoidal-shaped, such connection is possible. This way, the chamber forms a geometrically xe2x80x9creversexe2x80x9d tapered surface. In such a reverse taper, the width of the insert widens with insert depth. Rather than a snap-fit, which, if the proper geometric and material configurations are chosen, could result in a permanent connection between the insert and the attachment, this arrangement permits a longitudinal sliding, non-permanent connection between the panel insert and the decorative attachment, as well as a friction fit, which could be effected by spring-biased members on the engaging surface of the attachment that can deploy into the channel of the attachment securing chamber once the attachment is pressed against the opening in the chamber.
According to another embodiment of the invention, a precast panel is disclosed. The panel includes a precast layer defined by an outward-facing surface and an inward-facing surface, and a panel insert integrally formed into the precast layer. The panel insert comprising a unitary structure similar to that of the first embodiment. Optionally, the panel further comprises at least one attachment connected to the attachment securing chamber. Preferably, the attachment is a decorative attachment, although utilitarian attachments, such as hangers, acoustic baffles, signs carrying printed indicia or lighting fixtures could also be used. Moreover, the common base of the panel securing chamber and the outward-facing surface of the precast layer can be substantially coplanar with one another. An inwardly-projecting integral spine is another optional feature, and can include apertures disposed along its length to facilitate improved connectivity with the precast layer. As with the previous embodiment, the attachment securing chambers can also include reverse taper or prismatic features to promote locking.
According to still another embodiment of the invention, a kit for adding decorative attachments to a precast panel is disclosed. The kit comprises a panel insert and at least one decorative attachment. The panel insert is similar to that described in the first embodiment. The decorative attachment includes a substantially outward-facing, or viewable, surface configured to present decorative indicia, and a substantially inward-facing surface with at least one protrusion that is configured to fit into the channel of the attachment securing chamber. xe2x80x9cDecorative indiciaxe2x80x9d may include shapes, colors, relief, printing or other aesthetic accoutrements. Optionally, the kit is configured such that upon assembly, the channel and the protrusion form a complementary engagement with one another, which can be a snap-fit relationship, such as between a plurality of prismatic members on respective channel and protrusion members. As with the previous embodiments, the complementary engagement between the channel and the attachment may come from male-female trapezoidal shapes joined together.
According to yet another embodiment of the invention, a method of manufacturing a precast panel specially configured to accept decorative attachments is disclosed. The method includes configuring a casting surface to accept form liners, placing at least one panel insert in a space defined by the form liners, pouring uncured precast material into the space defined by the form liners such that the precast material at least partially occupies the space defined by interlocking chambers within the panel insert, and curing the precast material. The panel insert comprises a unitary structure substantially similar to that described in the first embodiment. Optionally, the method includes the additional step of securing a decorative attachment to the outer locking chamber once the precast material has cured. Preferably, the attachment securing chamber and a mating surface on the decorative attachment are either matingly shaped or include numerous shaped members on their respective surfaces such that when joined, an interlocking connection is formed. Thus, both the relatively non-permanent connection (through, for example, slidable or frictional fit) and the relatively permanent connection of the snap-fit surfaces can define an xe2x80x9cinterlockingxe2x80x9d connection. If necessary, the panel insert can be temporarily secured to either the panel-forming surface or the form liners prior to pouring the precast material to ensure that the panel insert does not move under the load of the precast material during pouring. As with the previous embodiment, the insert may include an inwardlyprojecting spine.
According to still another embodiment of the invention, a method of attaching a decorative object to a precast panel is disclosed. The method includes configuring the panel to include at least one panel insert in at least one of its surfaces, and joining the decorative object to an interlocking chamber that makes up the panel insert, which is a unitary structure similar to that defined by the first embodiment. Optionally, the step of joining between the decorative object and the attachment securing chamber is defined by a male-female connection, where the male-female connection comprises either a connection of interlocking prismatic members capable of a snap-fit, or a substantially trapezoidal detent slidably disposed within a substantially trapezoidal cavity defined by the attachment securing chamber. The panel insert may further include at least one inwardly-projecting integral spine to enhance attachment between the insert and the panel. Also as with the previous embodiments, the spine may include apertures to enhance panel insert attachment to the panel.